Ink (printing ink) is an important material for printing. It displays patterns and words on the substrate through printing. Ink includes main components and auxiliary components, which are evenly mixed and rolled repeatedly to form a viscous colloidal fluid. It is composed of pigments, binders, additives and solvents. It is used for various printing of books and periodicals, packaging and decoration, architectural decoration and so on. With the increase of social demand, the varieties and output of ink are also expanded and increased accordingly.